Latin name of the genus and species of plant claimed: Thunbergia alata. 
Variety denomination: xe2x80x98Lemon Starxe2x80x99.
The present invention comprises a new and distinct Thunbergia plant, botanically known as Thunbergia alata, and hereinafter referred to by the cultivar name xe2x80x98Lemon Starxe2x80x99.
The new Thunbergia resulted from an induced chemical mutation of the seed variety Thunbergia alata (not patented). The xe2x80x98Lemon Starxe2x80x99 cultivar was discovered and selected by the inventor in 1999, at Rheinfelden, Germany. xe2x80x98Lemon Starxe2x80x99 is vegetatively reproduced rather than produced from seed, is more vigorous and has darker flower color than the parent.
Asexual reproduction of the new cultivar by terminal tip cuttings has demonstrated that the characteristics of the new cultivar as herein described are firmly fixed and retained through successive generations of such asexual propagation.
It was found that the cultivar of the present invention:
(a) exhibits bright yellow flowers;
(b) forms dark green foliage;
(c) exhibits a good branching character; and
(d) exhibits a vigorous climbing and trailing growth habit.
The new cultivar of the present invention can be compared to xe2x80x98Susie Yellowxe2x80x99 (not patented). In side by side comparisons, plants of the new cultivar exhibit a more vigorous growth habit, larger leaves and brighter yellow flowers than those of xe2x80x98Susie Yellowxe2x80x99.